The inventive concept herein relates to a memory device, and more particularly, to a method of operating a memory system, which may control a program method and a read method to increase data reliability.
Semiconductor memory devices may be memory devices that are embodied using semiconductors, such as silicon (Si), germanium (Ge), gallium arsenide (GaAs), or indium phosphide (InP). The semiconductor memory devices may generally be classified into volatile memory devices and non-volatile memory devices.
Volatile memory devices are memory devices that lose stored data when power supply is cut off. Volatile memory devices may include static RAM (SRAM), dynamic RAM (DRAM), and synchronous DRAM (SDRAM). In contrast, non-volatile memory devices are memory devices that retain stored data even after power supply is cut off. Non-volatile memory devices may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable and programmable ROM (EEPROM), flash memory devices, phase-change RAM (PRAM), magnetic RAM (MRAM), resistive RAM (RRAM), and ferroelectric RAM (FRAM). Flash memory devices may be broadly divided into NOR type and NAND type.
Recent research has improved the integration density of semiconductor memory devices by adopting 3-dimensional array structures, and has suggested program methods and read methods of 3-dimensional memories.